Chernobai N. Temperature dependence of osmotic reactions of steroid-producing tissues and SPEV cells in cryoprotectant solutions.

Subject - the osmotic reactions of interstitium testis, adrenal and SPEV cells in contact with hypertonic solutions of cryoprotectants and hypothermia. Aim - to determine the geometrical and transport properties of steroid-producing tissues and SPEV cells in the cryoprotectants solutions for predicting the osmotic behavior of cells at different stages of cryopreservation. Methods: - morphometric analysis, methods of light microscopy and volyumometric method, physical-mathematical modeling, supravital staining with trypan blue, the statistical analysis.The thesis covers studying of transport characteristics of steroid-producing tissues and SPEV cells in cryoprotectant solutions, that essential for prediction of osmotic cell behavior at different stages of cryopreservation. Values of relative osmotically inactive volume of testicular and adrenal cell membranes, values of permeability coefficients of these and SPEV cells for molecules of glycerol, ethylene glycol, dimethyl sulfoxide, 1,2-butanediol and dimethyl formamide at temperature 5, 20 and 35oC have been determined by the volumetric method. In this work there have been determined the values of activation energy of cryoprotective agents (CPA) molecules transport through the membranes under research cells. There have been estimated a preservation of testicular cell membranes after freeze-thawing with glycerol, ethylene glycol, dimethyl sulfoxide and dimethyl formamide using different cooling rates. Using different cooling rates and the studied CPA a theoretical prediction of osmotic behavior of testicular cell membranes at different stages of cryopreservation has been made.